有人知道如何求这个问题吗

Question

Answer 1

#include <stdio.h>
int main()
{
    float fw;
    int w,t,fy=10;
    scanf("%f",&fw);
    w = fw;
    if(fw - w > 0)
          w++;
    t = w/10;
    switch(t)
    {
        default:
        {
           fy += (w-30)*6;
           w = 30;
        }
        case 1:
        case 2:
        {
            fy += (w-10)*5;
            w = 10;
        }
        case 0:
        {
              fy += (w-1)*4;
        }
    }
    printf("%d",fy);
    return 0;
}